feat(item): 添加物品详情页面并优化物品列表

- 新增 DetailItemScreen 组件，用于展示物品详细信息
- 在 ItemListScreen 中添加物品列表项的点击事件，跳转到物品详情页面- 修改 Item 模型，将 isInUse 字段类型从 String改为 String?
- 更新数据库表结构，将 is_in_use 列类型从 INTEGER 改为 TEXT

lib/database/item_table.dart

@@ -6,7 +6,7 @@ CREATE TABLE items (
   location_id INTEGER,
   description TEXT,
   purchase_date TEXT,
-  is_in_use INTEGER DEFAULT 0,
+  is_in_use TEXT DEFAULT 'no',
   created_at TEXT DEFAULT (datetime('now')),
   updated_at TEXT DEFAULT (datetime('now'))
 );

lib/models/item_model.dart

@@ -11,7 +11,7 @@ class Item {
   // 购买日期
   final DateTime? purchaseDate;
   // 是否使用
-  final String isInUse;
+  final String? isInUse;
   final DateTime? createdAt;
   final DateTime? updatedAt;
 
@@ -29,7 +29,6 @@ class Item {
 
   Map<String, dynamic> toMap() {
     return {
-      'id': id,
       'name': name,
       'category_id': categoryId,
       'location_id': locationId,

lib/screens/item_list_screen.dart

@@ -1,8 +1,10 @@
 import 'package:flutter/material.dart';
 import 'package:item_tracker/provider/item_provider.dart';
-import 'package:item_tracker/screens/addItem/add_item_screen.dart';
+import 'package:item_tracker/screens/item_screens/add_item_screen.dart';
 import 'package:provider/provider.dart';
 
+import 'item_screens/detail_item_screen.dart';
+
 class ItemListScreen extends StatefulWidget {
   @override
   _ItemListScreenState createState() => _ItemListScreenState();
@@ -46,6 +48,14 @@ class _ItemListScreenState extends State<ItemListScreen> {
                   return ListTile(
                     title: Text(item.name),
                     subtitle: Text(item.description ?? ""),
+                    onTap: () {
+                      Navigator.push(
+                        context,
+                        MaterialPageRoute(
+                          builder: (context) => DetailItemScreen(item: item),
+                        ),
+                      );
+                    },
                   );
                 }));
       }),

lib/screens/item_screens/detail_item_screen.dart

@@ -0,0 +1,27 @@
+import 'package:flutter/material.dart';
+import 'package:item_tracker/models/item_model.dart';
+
+class DetailItemScreen extends StatelessWidget {
+  final Item item;
+
+  DetailItemScreen({required this.item});
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text('${item.name}'),
+      ),
+      body: Padding(
+        padding: EdgeInsets.all(16.0),
+        child: Column(
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Text('名称: ${item.toMap().toString()}'),
+            Text('描述: ${item.description}')
+          ]
+        )
+      )
+    );
+  }
+}